refactor: simplify scope-security MR

Drop null-prototype passthrough in push(), inline blocked-key checks,
remove redundant createScope at include tag, trim verbose docs, and
drop implementation-detail unit tests.

Co-authored-by: Cursor <[email protected]>

src/context/context.ts

@@ -95,11 +95,7 @@ export class Context {
     return scope
   }
   public push (ctx: Scope): Scope {
-    const scope = ctx instanceof Drop
-      ? ctx
-      : Object.getPrototypeOf(ctx) === null
-        ? ctx
-        : createScope(ctx)
+    const scope = ctx instanceof Drop ? ctx : createScope(ctx)
     this.scopes.push(scope)
     return scope
   }

src/tags/include.ts

@@ -1,5 +1,5 @@
 import { Template, ValueToken, TopLevelToken, Liquid, Tag, assert, evalToken, Hash, Emitter, TagToken, Context } from '..'
-import { BlockMode, Scope, createScope } from '../context'
+import { BlockMode, Scope } from '../context'
 import { Parser } from '../parser'
 import { Argument, Arguments, PartialScope } from '../template'
 import { isString, isValueToken } from '../util'
@@ -40,7 +40,7 @@ export default class extends Tag {
     const scope = (yield hash.render(ctx)) as Scope
     if (withVar) scope[filepath] = yield evalToken(withVar, ctx)
     const templates = (yield liquid._parsePartialFile(filepath, ctx.sync, this.currentFile)) as Template[]
-    ctx.push(ctx.opts.jekyllInclude ? { include: createScope(scope) } : scope)
+    ctx.push(ctx.opts.jekyllInclude ? { include: scope } : scope)
     yield renderer.renderTemplates(templates, ctx, emitter)
     ctx.pop()
     ctx.restoreRegister(saved)